Slide rule



Patented July 2, 1946 UNITED STATES PM'ENT oEFlcE SLIDE RULE SamuelLerner, Pawtucket, R. I.

Application March 20, 1944, Serial No. 521,296

(Cl. 23S-70) 1 Claim.

This invention relates to a slide rule, more particularly to thephysical form of the slide rule.

Slide rules are usually in the form of a flat elongated shape withscales on the opposite flat surfaces and with a slide capable of beingturned over for cooperation with the scales on either fiat surface.

One of the objects of this invention is to provide two telescopingmembers, the outer of which carries a scale and is transparent while theother cooperates therewith that the parts may be held together by reasonof their nesting relation.

Another object of the invention is to make available shifting from onescale to the other by merely turning the members about their commonaxis, whereby all of the scales provided will be equally prominent whenthe device is rotated from one position to another.

Another object of this invention is to provide a compact arrangement ofthe parts and an arrangement so that the device may be readily held inthe pocket of the user to be carried on the person.

A further object of this invention is to provide an arrangement of theparts so that the physical structure may house parts for other uses, forinstance as a pencil or the like.

Another object of this invention is to provide for changing the size ofthe scale surface by a modification of the diameter of the cylinderrather than to change the width of a flat device as heretofore usuallyused.

With these and other objects in view, the invention consists of certainnovel features of construction, as will be more fully described andparticularly pointed out in the appended claim.

In the accompanying drawing:

Fig.1 shows my rule as applied to a pencil;

Fig. 2 shows-the cylindrical pencil body;

Fig. 3 is an elevation of the tubular slide which may be telescoped onthe body;

Fig. 4 is an end view of the structure shown in Fig. 3;

Fig. 5 is a section on line 5-5 of Fig. 2;

Fig. 6 is a section of the slider alone;

Fig. '1 is a sectional view on line 1-1 of Fig. 1;

Fig. 8 is a longitudinal sectional view of the cursor;

Fig. 9 is an end view showing a modied form of slide.

With reference to the drawingJ have provided a cylindrical body I0 whichas here shown has the form of a mechanical pencil with its shell taperedat one end II within which shell the mechanical pencil structure may behoused for the projection of a lead I2, while an eraser I3 may beprovided at the opposite end of the body. Scales designated generally Aand designated generally D are laid off in logarithmic values on thesurface of the body I0.

A slide designated generally I4 comprises a transparent cylindricalmember through which the A and D scales on the body I0 may be viewed.Its internal diameter I5 is of a size to slidingly fit the outercylindrical surface I8 of the body I0. This member carries on itssurface engraved marking designated as the B, C, and Cl scales, as shownin Fig. 3, to cooperate with the scales A and D and may carry additionalscales at .|1, I8, and I9 as shown in section in Fig. 4.

In order to maintain the members III and I4 in adjusted relation grooves29 and 2| are provided in the body I0 for the reception of resilientleaf springs 22 and 23 located adjacent either end portion of the memberI4. These springs will fit into either of the grooves 20, 2l andmaintain the members in relative position against rotation so that theymay be slid one on the other. If it is desired to relatively move theslide through the resilient portions 22 and 23 will be transferred fromthe groove 20 to the groove 2|.

In some cases instead of having the seamless tube I4 for one member thetube may be formed as shown at 25 in Fig. 9, of a fiat sheet so as toprovide overlapping portions 26 while the resilient retaining springs 21will be provided at the overlapping portions. In some cases this part 21may be fixed and the resiliency of the stock depended upon for holdingthe tubular member adjusted pon the body.

The cursor or third member designated 30, as shown ln-Fig. 8, consistsof a transparent cylindrical. member 3| having a resilient spring 33 forfriction` against the member I4 upon which it slidingly fits and may bemoved therealong. Datum lines 32 on the outer surface and 32' on theinner surface of the member 3l are provided for convenience of the eyein determining a certain position on the scale for easy reading. Afinger clip 34 is resiliently mounted as at 35 and may be swungoutwardly at its knob end 36 by pressure on the piece 31. The knob endwill also move along and engage the member I4 for friction therewith andmay also be used as a clip for retaining the entire device in the pocketof the user when desired.

'Ihe members I0 and I4 may be relatively moved for determination ofdesired calculations, the slider being moved to assist in reading. Thedatum line 32 on the outer surface of the slider 3 is aligned with thedatum line I2' on the inner suriaeethereofwhenrcadingthsscalessolstoavoid parallax in observation through the slider il and through theslide il.

I claim- A calculating instrument comprising a cylindrical body member,having a scale thereon, a transparent cylindrical tubular member havinga bore of a size to slidingly tit said body member,

4 telescoping thereover and having scale thereon cooperatingr with thescale on the bow, and a cylindrical cursor member of transparentmaterial slidably fitting said tubular member and having two datum linesone on its inner surface and the other on its outer surface, said linesbeing in a plane at right angles to the scales on said body andcylindrical members.

SAMUEL LERNER.

